1. Field of the Invention
The present invention relates to a system for accumulating exposure energy information of a wafer and a management method of a mask for exposure utilizing exposure energy information of the wafer accumulated with the system in which in a photo lithography process of a semiconductor, the exposure degree of the mask relating to the exposure energy as direct causes of the mask contamination such as the crystal growth and haze is directly accumulated and calculated by using the light energy information caused by the wafer exposure executed by means of an original plate (mask/reticle) with a circuit patterned by an exposing apparatus such as a stepper/scanner, thereby predicting a defect of the mask and accordingly then increasing the yield of a semiconductor.
2. Description of the Related Art
Generally, in an exposing apparatus such as a stepper/scanner, which had been widely used conventionally, a light source such as a mercury lamp or an excimer laser is used as an exposure energy source in order to form a pattern on the wafer and then the light generated from the light source is passed through the mask/reticle with the incised circuit and reached finally to the wafer with the coated photo resist, so that the pattern on the mask/reticle is transferred to the wafer.
Recently, the circuit pattern is formed minutely more and more and accordingly, a light source with a short wavelength range (365 nm(I-Line lamp)→248 nm(KrF)→193 nm(ArF)→15 nm(EUV)) is used in order to obtain the enhanced resolution. According this, a mask is exposed to high light energy and also, the diameter of a wafer is increased like 200 mm, 300 mm and 450 mm, the exposure energy and exposure time per the wafer are increased, so that the mask is exposed to the high light energy during the long time. By the rising action like this, the mask contamination such as the crystal growth and the haze is progressed more rapidly and the more serious mask defect is generated.
And, in the conventional art, the management of the mask has been performed arbitrarily by measuring the crystal on a mask or the degree of contamination without information on the exposing energy as the direction reason of the contamination as the occasion demands. According this, there are several disadvantages that the preventive management can not be performed and the yield of the semiconductor can not be increased according to the use of the contaminated mask.